1. Field of the Invention
The invention generally relates to a capacitive touching apparatus, and more particularly, to a capacitance variation detection circuit of a capacitive touching apparatus.
2. Description of Related Art
Along with the population of electronic technology, a very important function of the current electronic products is to provide an electronic apparatus able to produce a high interactivity with the user thereof, in which the touching panel techniques takes the first place to be the most effective one directly providing a man-machine interactive technique.
Touching apparatuses can be roughly divided into several types, for example, resistive touching apparatus, capacitive touching apparatus and projection touching apparatus. Taking a capacitive touching apparatus as an exemplary example, FIG. 1 is a circuit diagram of a conventional capacitive touching apparatus 100. Referring to FIG. 1, the capacitive touching apparatus 100 includes an integrator 110 connecting a plurality of touch capacitors 120-140 so as to detect the variation of the capacitance value thereof. When conducting detecting the variation of the capacitance value on one of the touch capacitors 120-140, a periodic oscillating signal IN is necessarily provided to the one of the touch capacitors 120-140. By means of the integrator 110, the voltage variations of the detected touch capacitors are obtained under applying a plurality of oscillating signals IN so as to detect the variations of the capacitance values of the touch capacitors to be detected.